A. Area of Invention
The invention relates to a lubrication system for an internal combustion engine, which is situated externally to the engine housing.
B. Prior Art
In the operation of an internal combustion engine, it is essential to provide sufficient lubrication of the engine parts to minimize the wear thereof. This normally occurs during operation of the engine. However, various problems may occur when the operative cycle of the engine is initiated, during an obstruction within the oil pump or the so-called oil galley which connects the oil pump to the fluid flow passages within the engine proper, and after the engine has been turned off.
In automotive engines, it is well-known that a vehicle used often and for relatively long periods of time over long distances will experience substantially less engine wear than one that is subjected to numerous starts and stops, that is, one that is used for driven upon many frequent short trips, notwithstanding that the total mileage of the latter may be substantially less than that of a vehicle that is driven frequently and for longer distances. Starting of an engine followed by a short trip, or starting of an engine followed by long periods of non-use is, particularly, prevalent in the marine area. As such, marine engines and standby generators are particularly susceptible to such engine wear. Therein it is estimated that between 70 and 80 percent of all engine wear occurs during the first ten to fifteen seconds of operation of the engine.
It has become accepted in the art that the problem that frequent starting of an engine before adequate oil circulation therein has commenced is advantageously addressed through some type of pre-lubricating system in which, either prior to ignition, or immediately thereafter, an auxiliary means of rapidly providing lubrication to the engine before it begins its normal function (including the lubrication associated therewith) is furnished. This recognition, particularly as it relates to automotive vehicles, is reflected in U.S. Pat. No. 3,197,0027 (1975) to Hakanson et al, entitled System for Pre-lubricating an Occasionally Used, Fuel Cranked, Quick Starting, Fuel Burning Engine; U.S. Pat. No. 4,936,272 (1990) to Whitmore, entitled Prelube System; and U.S. Pat. No. 5,121,720 (1992) to Roberts, entitled Pre-Ignition Lubricating System.
Further, in turbo-charged engines, it is imperative to provide a proper level of oil to the turbo bearings after the engine is shut-down. This issue is rarely addressed in the prior art. More particularly, there does not, to the knowledge of the within inventor, exist an integrated pre- and post-ignition, or other lubrication system, particularly adapted to the geometry and needs of internal combustion engines, nor is there known an external lubrication system of such type capable of providing additional important functions of over-pressure protection, timing control and oil drainage. The instant invention therefore addresses the long-felt need in the vehicle engine art for a single unitary externally positioned system combining, within a single fluid circuit, functions of pre- and post-lubrication, over-pressure protection, timing control and drainage of engine oil.